Agriculture is one of the most hazardous occupations in the United States, and rural adolescents are at significant risk of agricultural- and work-related injury and asthma. Based on U.S. Census Bureau estimates, approximately 100,000 adolescents between 14 and 18 years old reside in rural Minnesota, and may be at risk for agricultural injuries and asthma. This study will use new surveillance methods to address the issues relevant to these adolescent injuries and asthma. The specific aims are to: (1) determine the magnitude and scope of agricultural injuries and asthma among 9th to 12th grade students in four different agricultural regions in Minnesota; (2) describe the change in rural work exposures in these adolescents in terms of total work hours, and hours worked between agribusiness, traditional family farming and non-farm work; (3) evaluate the reliability of adolescent self-reported information about agricultural and work exposures, and injury experiences; and (4) use a cohort analysis to calculate risk factors for injuries and to facilitate planning for future prevention activities. An advisory group consisting of professionals in public health, agricultural education, school administration and others will assist in meeting these aims. Using a stratified cluster design with agricultural region as strata and schools as the cluster, a sample of 32 rural schools will be selected and recruited to participate in this study. Data on demographics, work hours and hazards, and injury risk factors will be collected from the entire student body through a self-completed questionnaire administered to each student a total of four times over a two-year period. Injury incidence and asthma prevalence rates will be calculated to determine the degree of variability on both a seasonal and yearly basis. Information will also be collected to determine the number and type of agricultural and work-related injuries that occur to rural adolescents across a spectrum of farming activities. Data also will be used to analyze this open (dynamic) cohort for potential risk factors.